Hi Caitlin, I tried so many ways as suggested but unsuccessful...and I realise that I need to filter the student ID and their CGPA, but if I change the ID into character I lost the CGPA value. It is easy to do in excel, however a bit time consuming and trying to do in R.
I have these data: dput(dt_all2) structure(list(FAC_CODE = structure(c(2L, 2L, 2L, 4L, 1L, 1L, 4L, 7L, 3L, 3L, 3L, 3L, 3L, 2L, 2L, 1L, 2L, 5L, 6L), .Label = c("FKASA", "FKEE", "FKKSA", "FKM", "FKP", "FSKKP", "FTK"), class = "factor"), STUDENT_ID = structure(c(9L, 6L, 7L, 17L, 2L, 3L, 18L, 19L, 13L, 12L, 14L, 15L, 16L, 10L, 8L, 1L, 5L, 11L, 4L), .Label = c("AA14068", "AB15103", "AB15124", "CC14107", "EA13043", "EB14059", "EB14073", "EB14101", "EC14021", "EC15063", "FB14085", "KA13142", "KA13143", "KA13156", "KE13034", "KE13046", "MA14071", "MA14115", "PA13048" ), class = "factor"), PROGRAM = structure(c(2L, 1L, 1L, 2L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 1L, 2L, 2L, 2L, 1L ), .Label = c("DIPLOMA", "IJAZAH SARJANA MUDA"), class = "factor"), CGPA = c(2.42, 3.27, 1.98, 2.85, 2.24, 3.01, 3.31, 2.88, 3.61, 3.69, 3.2, 3.85, 3.63, 2.67, 2.35, 2.74, 1.96, 2.89, 2.59)), .Names = c("FAC_CODE", "STUDENT_ID", "PROGRAM", "CGPA" ), class = "data.frame", row.names = c(NA, -19L)) and I want to filter my data as follows: > dput(dt_all3) structure(list(FAC_CODE = structure(c(2L, 2L, 4L, 4L, 5L, 1L, 6L, 3L, 3L, 3L, 3L, 3L, 2L), .Label = c("FKASA", "FKEE", "FKKSA", "FKM", "FKP", "FTK"), class = "factor"), STUDENT_ID = structure(c(4L, 3L, 11L, 12L, 5L, 1L, 13L, 7L, 6L, 8L, 9L, 10L, 2L), .Label = c("AA14068", "EA13043", "EC14021", "EC15063", "FB14085", "KA13142", "KA13143", "KA13156", "KE13034", "KE13046", "MA14071", "MA14115", "PA13048" ), class = "factor"), PROGRAM = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = "IJAZAH SARJANA MUDA", class = "factor"), CGPA = c(2.67, 2.42, 2.85, 3.31, 2.89, 2.74, 2.88, 3.61, 3.69, 3.2, 3.85, 3.63, 1.96)), .Names = c("FAC_CODE", "STUDENT_ID", "PROGRAM", "CGPA"), class = "data.frame", row.names = c(NA, -13L )) I would like to select the student id where the third and fourth value represent the year they register data is eg. AA15..., AE14,... and I would also to select their cgpa value. Thank you. On Mon, Mar 13, 2017 at 2:26 PM, roslinazairimah zakaria < roslina...@gmail.com> wrote: > Thank you so much for your help. > > On Mon, Mar 13, 2017 at 1:52 PM, bioprogrammer <bioprogram...@gmail.com> > wrote: > >> Hi. >> >> I would use the "substr" function: >> >> https://stat.ethz.ch/R-manual/R-devel/library/base/html/substr.html >> >> ...assuming you're working with character data. >> >> Another useful skill involves working with regular expressions. >> >> http://www.endmemo.com/program/R/grep.php >> >> http://regular-expressions.mobi/tutorial.html >> >> Hope these help :) >> >> ~Caitlin >> >> >> >> >> >> Sent from my T-Mobile 4G LTE Device >> >> >> -------- Original message -------- >> From: roslinazairimah zakaria <roslina...@gmail.com> >> Date:03/12/2017 10:18 PM (GMT-07:00) >> To: Bert Gunter <bgunter.4...@gmail.com> >> Cc: r-help mailing list <r-help@r-project.org> >> Subject: Re: [R] Extract student ID that match certain criteria >> >> Another question, >> >> How do I extract ID based on the third and fourth letter: >> >> I have for example, AA14004, AB15035, CB14024, PA14009, PA14009 etc >> >> I would like to extract ID no. of AB14..., CB14..., PA14... >> >> On Mon, Mar 13, 2017 at 12:37 PM, roslinazairimah zakaria < >> roslina...@gmail.com> wrote: >> >> > Hi Bert, >> > >> > Thank you so much for your help. However I don't really sure what is >> the >> > use of y values. Can we do without it? >> > >> > x <- as.character(FKASA$STUDENT_ID) >> > y <- c(1,786) >> > My.Data <- data.frame (x,y) >> > >> > My.Data[grep("^AA14", My.Data$x), ] >> > >> > I got the following data: >> > >> > x y >> > 1 AA14068 1 >> > 7 AA14090 1 >> > 11 AA14099 1 >> > 14 AA14012 786 >> > 15 AA14039 1 >> > 22 AA14251 786 >> > >> > On Mon, Mar 13, 2017 at 11:51 AM, Bert Gunter <bgunter.4...@gmail.com> >> > wrote: >> > >> >> 1. Your code is incorrect. All entries are character strings and must >> be >> >> quoted. >> >> >> >> 2. See ?grep and note in particular (in the "Value" section): >> >> >> >> "grep(value = TRUE) returns a character vector containing the selected >> >> elements of x (after coercion, preserving names but no other >> >> attributes)." >> >> >> >> >> >> 3. While the fixed = TRUE option will work here, you may wish to learn >> >> about "regular expressions", which can come in very handy for >> >> character string manipulation tasks. ?regex in R has a terse, but I >> >> have found comprehensible, discussion. There are many good gentler >> >> tutorials on the web, also. >> >> >> >> >> >> Cheers, >> >> Bert >> >> >> >> Bert Gunter >> >> >> >> "The trouble with having an open mind is that people keep coming along >> >> and sticking things into it." >> >> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) >> >> >> >> >> >> On Sun, Mar 12, 2017 at 8:32 PM, roslinazairimah zakaria >> >> <roslina...@gmail.com> wrote: >> >> > Dear r-users, >> >> > >> >> > I have this list of student ID, >> >> > >> >> > dt <- c(AA14068, AA13194, AE11054, AA12251, AA13228, AA13286, >> AA14090, >> >> > AA13256, AA13260, AA13291, AA14099, AA15071, AA13143, AA14012, >> AA14039, >> >> > AA15018, AA13234, AA13149, AA13282, AA13218) >> >> > >> >> > and I would like to extract all student of ID AA14... only. >> >> > >> >> > I search and tried substrt, subset and select but it fail. >> >> > >> >> > substr(FKASA$STUDENT_ID, 2, nchar(string1)) >> >> > Error in nchar(string1) : 'nchar()' requires a character vector >> >> >> subset(FKASA, STUDENT_ID=="AA14" ) >> >> > [1] FAC_CODE FACULTY STUDENT_ID NAME PROGRAM >> KURSUS >> >> > CGPA ACT_SS ACT_VAL ACT_CS ACT_LED ACT_PS >> >> > ACT_IM >> >> > [14] ACT_ENT ACT_CRE ACT_UNI ACT_VOL... >> >> > >> >> > Thank you so much for your help. >> >> > >> >> > How do I do it? >> >> > -- >> >> > *Roslinazairimah Zakaria* >> >> > *Tel: +609-5492370 <+60%209-549%202370>; Fax. No.+609-5492766 >> <+60%209-549%202766>* >> >> > >> >> > *Email: roslinazairi...@ump.edu.my <roslinazairi...@ump.edu.my>; >> >> > roslina...@gmail.com <roslina...@gmail.com>* >> >> > Faculty of Industrial Sciences & Technology >> >> > University Malaysia Pahang >> >> > Lebuhraya Tun Razak, 26300 Gambang, Pahang, Malaysia >> >> > >> >> > [[alternative HTML version deleted]] >> >> > >> >> > ______________________________________________ >> >> > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> >> > https://stat.ethz.ch/mailman/listinfo/r-help >> >> > PLEASE do read the posting guide http://www.R-project.org/posti >> >> ng-guide.html >> >> > and provide commented, minimal, self-contained, reproducible code. >> >> >> > >> > >> > >> > -- >> > *Roslinazairimah Zakaria* >> > *Tel: +609-5492370 <+60%209-549%202370> <+60%209-549%202370>; Fax. No. >> +609-5492766 <+60%209-549%202766> >> > <+60%209-549%202766>* >> > >> > *Email: roslinazairi...@ump.edu.my <roslinazairi...@ump.edu.my>; >> > roslina...@gmail.com <roslina...@gmail.com>* >> > Faculty of Industrial Sciences & Technology >> > University Malaysia Pahang >> > Lebuhraya Tun Razak, 26300 Gambang, Pahang, Malaysia >> > >> >> >> >> -- >> *Roslinazairimah Zakaria* >> *Tel: +609-5492370 <+60%209-549%202370>; Fax. No.+609-5492766 >> <+60%209-549%202766>* >> >> *Email: roslinazairi...@ump.edu.my <roslinazairi...@ump.edu.my>; >> roslina...@gmail.com <roslina...@gmail.com>* >> Faculty of Industrial Sciences & Technology >> University Malaysia Pahang >> Lebuhraya Tun Razak, 26300 Gambang, Pahang, Malaysia >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide http://www.R-project.org/posti >> ng-guide.html >> and provide commented, minimal, self-contained, reproducible code. >> > > > > -- > *Roslinazairimah Zakaria* > *Tel: +609-5492370 <+60%209-549%202370>; Fax. No.+609-5492766 > <+60%209-549%202766>* > > *Email: roslinazairi...@ump.edu.my <roslinazairi...@ump.edu.my>; > roslina...@gmail.com <roslina...@gmail.com>* > Faculty of Industrial Sciences & Technology > University Malaysia Pahang > Lebuhraya Tun Razak, 26300 Gambang, Pahang, Malaysia > -- *Roslinazairimah Zakaria* *Tel: +609-5492370; Fax. No.+609-5492766* *Email: roslinazairi...@ump.edu.my <roslinazairi...@ump.edu.my>; roslina...@gmail.com <roslina...@gmail.com>* Faculty of Industrial Sciences & Technology University Malaysia Pahang Lebuhraya Tun Razak, 26300 Gambang, Pahang, Malaysia [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.